Evaluation technique of kinetic parameters for irreversible charge transfer reactions from steady-state voltammograms at microdisk electrodes
Evaluation technique of kinetic parameters for irreversible charge transfer reactions from steady-state voltammograms at microdisk electrodes
复制标题
DOI：
10.1016/j.elecom.2005.03.006
复制
发表时间：
2005-05
影响因子：
5.4
通讯作者：
K. Aoki
中科院分区：
文献类型：
--
作者：
K. Aoki
在前人解析方法的基础上，由扩散方程和Butler-Volmer方程推导出微盘电极不可逆稳态电流-电压曲线半波电位的显式近似表达式[K.青木，K.德田，H.松田，J.电肛门。化学。 235（1987）87]。半波电位 E1/2 与 ln(1−exp(−(E1/2−E0))F/RT) 的关系图显示与 RT/αF 的斜率呈线性关系，与动力学参数的值无关，其中 a 是电极的半径，α 是传递系数。该图中两个轴上的值可以很容易地从伏安图中获得。截距给出了速率常数。尽管两个模型电极上的电流分布存在很大差异，但从圆盘模型获得的动力学参数值与从半球模型获得的动力学参数值非常接近。
An explicit approximate expression for half-wave potentials of irreversible steady-state current-voltage curves at a microdisk electrode was derived from the diffusion equation and the Butler–Volmer equation on the basis of the previous analytical method [K. Aoki, K. Tokuda, H. Matsuda, J. Electroanal. Chem. 235 (1987) 87]. The plot of the half-wave potential, E1/2against ln(1−exp(−(E1/2−E0))F/RT) showed a linear relation with the slope of RT/αF, irrespective of the values of the kinetic parameters, where a is the radius of the electrode and α is the transfer coefficient. Values on the both axis in this plot are readily accessible from the voltammograms. The intercept gave the rate constant. Values of kinetic parameters obtained from the disk model were very close to those from the hemisphere model although there is big difference in current distribution on the two model electrodes.